kindred build how do you build them ?
1th item
<-- one of these 2
im not sure wich one yet cause they dont need sustain i dont feel like they need the slow either
but devourer cause i i feel like their kit goes better with atk speed than atk dmg and il be building botrk next wich goes better with atk speed
2th
works good with passive atk speed and % dmg be sure to focus on getting your stacks so that you have both this one and your 6stacks atleast
3th
far superior than
id say for this build and kindred cause it goes well with atck speed, and lowers the armor on the target not only for you but also for your team mates since you most likely have another adc in your team
from here on im not really sure what to build usualy since your aplying on hit effects for most of your dmg comes from botrk and your passive it would make allot of sence to build 
on the other hand where black cleaver makes you more tanky
would be like adding a warmogs to your build while gaining atk dmg and a verry strong passive
ofcourse i could also go for an infinity edge triforce blood thirster or a deffence item
or
to increase the healing on that auto attack that regen your health